Surface Barkhausen noise (SBN) and encircle Barkhausen noise (EBN) measurements have been made on pipeline steel under different positive and negative DC bias field conditions. The effects of bias field on both SBN and EBN are found to be similar. With increasing positive and negative bias the Barkhausen noise (BN) is found to decrease, and at higher bias fields the BN disappears. The results confirm that magnetization in the low-field region (below 0.5 T) takes place by 180sup(o) wall motion which gives rise to magnetic BN. Tensile and compressive stresses have been applied in a section of the pipe and SBN measurements made. The SBN voltage is found to increase with tension and to decrease with compression.